Just according to the following instructions:

Step 1:Make a decision of which items you want to donate and then confirm the total account.
There are 5 cases for Sims2 ：
Case 1:Donate for 4 hairs,the price is $6.5 (Save $3.5)

Case 2: Donate for 7 hairs,the price is $10 (Save $7.5)

Case 3: Donate for 14 hairs,the price is $16.9 (Save $18.1)

Case 4: Donate for 25 hairs,the price is $25.0 (Save $37.5)

Case 5:Donate for All hairs,the price is $49 (Save $128)

Step 2:Go to http://www.paypal.com and login your paypal account,and then click the button "send money" (view pic 1.).

Step 3:Fill in the form according to your instance(for example:view pic 2.),and then click the button "continue"(view pic 2.).

Step 4:Just check the information and then click the button "Send money"(view pic 3)